When using a switcher box on a parallel port to use both the FlyerPC and a printer, keep in mind that both drivers may be tryiong to access the port at the same time, even if you are only trying to do one or the other. Here are some suggestions:

In Cakewalk, deselect the MIDI Drievers when you're trying to print. Go into Settings|MIDI devices and un-highlight all ins and outs for the PCFlyer.

In FreeStyle, you must select and alternate MIDI Driver, even if it's a dummy driver that's not addressing another card. FreeStyle can't run without SOME MIDI driver selected.